Lithium-based batteries are used in a variety of applications, such as videotape recorders, communication devices and many portable devices. Traditionally, the lithium battery industry has employed LiCoO2-type materials as the active component of lithium battery cathodes. However, LiCoO2 lithium battery cathodes typically are expensive and exhibit relatively low capacity.
One alternative to the use of LiCoO2-based cathode materials is LiNiO2-based materials, which generally are less expensive, but often exhibit higher specific capacity. Typically, LiNiO2-based materials employed in lithium battery cathodes have a lithium content of about 80% and a cobalt content of about 20% (atomic weight percent). However, LiNiO2-based materials generally are less safe (i.e. exhibit more gassing) than are LiCoO2-type materials. Further, LiNiO2-based materials exhibit a first cycle efficiency that often is between about five and ten percent lower than that of LiCoO2-based cathodes. Generally, LiCoO2-based materials have efficiencies in a range of between about 93% and about 95%, whereas LiNiO2-based materials have efficiencies that range from between about 83% to about 88%.
Other cathode materials known in the art include, for example, those having a chemical formula Li1-XAXNi1-YBYO2, wherein “A” represents and alkali or alkaline earth metal element, and “B” represents at least one transition metal. It is believed that cathode materials having this composition often exhibit little or no improvement over more traditional materials.
Therefore, a need exists for cathode materials suitable for use in lithium-based batteries that minimize or overcome the above-referenced problems.